The twin epidemics of obesity and diabetes are overwhelming healthcare systems worldwide, and these conditions create an increased risk for heart disease, cancer, and mental disorders. Improved diagnostic tests and therapies to detect and treat obesity, diabetes, and their complications requires the use of model systems that are relevant to human disease. These include human cell systems and complementary non-human primate models that are more likely to predict efficacy in human patients.
Specific research projects:
The Roberts laboratory has a long-term focus on various aspects of insulin and insulin-like growth factor signaling, which have crucial roles in mammalian growth and development, metabolic control, and tumorigenesis. Areas currently under investigation are:
- Regulation of adipose tissue function. We have developed an ex vivo system for analysis of fatty acid uptake in rhesus macaque adipose tissue and are investigating the gender-specific action of androgens on insulin action.
- Control of insulin secretion in primate islets. We are determining the role of incretin hormones such as GLP-1 on insulin secretion and islet function, including potential effects on alpha cells.
- Analysis of novel insulin and glucagon analogs. We are determining the in vitro efficacy of novel insulin analogs and new formulations of glucagon to evaluate their potential utility in a bi-hormonal, closed-loop artificial pancreas device.
Charles Roberts is Associate Director for Research and Senior Scientist in the Divisions of Diabetes, Obesity, and Metabolism and Reproductive and Developmental Sciences at the Center, and Professor of Medicine, Pediatrics, and Cell and Developmental Biology at OHSU. He received his Ph.D. in biochemistry and molecular biology at the University of California, Santa Barbara (UCSB), in 1975. Following an American Cancer Society-supported postdoctoral fellowship, he was an Assistant Professor of Biological Sciences at UCSB from 1978-1984. He was then recruited to the Diabetes Branch at the National Institutes of Health in 1984 as a Special Expert, was appointed Associate Chief of the Section of Molecular Physiology in 1989 with tenure, and promoted to Senior Investigator in 1992. In 1994, Dr. Roberts came to OHSU as Professor of Pediatrics and Associate Chair for Research. He moved to the Center in 2007.
Recent PublicationsVarlamov, O., Chu, M., McGee, W., Cameron, J., O’Rourke, R.O., Meyer, K., Bishop, C., Stouffer, R., and Roberts, C.T., Jr. Ovarian cycle-specific regulation of adipose tissue lipid storage by testosterone in female non-human primates. Endocrinology 154:4126-4135 (2013).
Menting, J.G., Yang, Y., Chan, S.J., Phillips, N.B., Smith, B.J. et al. A protective hinge in insulin opens to enable receptor engagement. Proc. Natl. Acad. Sci. USA 111:E3395-E3404 (2014).
Yuen, K.C.J., Roberts, C.T., Jr., Frystyk, J., Rooney, W.D., Pollaro, J.R., Brandon, D.D., Klopfenstein, B.J., and Purnell, J.Q. Short-term low-dose GH therapy improves insulin sensitivity without modifying cortisol metabolism and ectopic fat accumulation in adults with GH deficiency. J. Clin. Endo. Metabol. 99:E1862-1869 (2014).
Chu, M., Cahana, D.Y., Kahl, C., Cornea, A., Sampath, H., Roberts, C.T., Jr., and Varlamov, O. Spatiotemporal dynamics of triglyceride storage in unilocular adipocytes. Mol. Biol. Cell 25:4096-4105 (2014).
Bakhtiani, P.A., Caputo, N., Castle, J.R., El Youssef, J., Carroll, J.M., David, L.L., Roberts, C.T., Jr., and Ward, W.K. A novel, stable aqueous glucagon formulation using ferulic acid as an excipient. J. Diabetes Sci. Tech. 9:3-7 (2015).
Varlamov, O., Chu, M., Cornea, A., Sampath, H., and Roberts, C.T., Jr. Cell-autonomous heterogeneity of nutrient uptake in white adipose tissue of rhesus macaques. Endocrinology 156:80-89 (2015).See a full listing of Dr. Roberts' publications